1. Field of the Invention
The present invention relates to a rolling bearing and a power transmission device including the rolling bearing.
2. Description of Related Art
In order to achieve torque reduction by reducing a viscous resistance of lubricant, there is a conventional rolling bearing as described in Japanese Patent Application Publication No. 2008-82547 (JP 2008-82547 A), for example. In the rolling bearing, a bubble generating device (a microbubble generator) is disposed outside the rolling bearing so that bubbles generated by the bubble generating device are mixed into lubricant, and then supplied to the rolling bearing. Thus, a viscous resistance of the lubricant is reduced.
However, in the rolling bearing described in JP 2008-82547 A, a dedicated bubble generating device for mixing bubbles into the lubricant and supplying them to the rolling bearing should be disposed outside the rolling bearing, which increases cost and also causes necessity to secure a space in which to dispose the bubble generating device.